An Equation

[emvella]

Hi,

I think this is impossible but I will take a chance because if it is possible it will save us lot of work and time.

At work I have a CAD software and I use equations to set X, Y, Z positions and material width, length and height. Equations are similar to Excel formulas. So if it works in Excel it will work in the CAD software.

I want a special equation that it ends always with same answer even if I change a particular number from the 4 or more numbers that I have in that equation. (when I say numbers they are positions and sizes of materials).

Example I have:

100+200+120+80=500

And I change 80 to 120, I still want the answer = 500 (means that a particular part stay same position and don't move even if I changed a size of another part).

Thanks

 

[oldbrewer]

so any or all of 100,200,120 need to lose 40 between them

you need to provide rules eg off the biggest, equally off all

or maybe the second number must be twice the first and the third number 20% bigger than the first.........

 

[davesexcel]

When you change 80 to 120, how is it decided what other numbers change to make the sum 500?

 

[emvella]

Hi Oldbrewer,

Yes in fact when I say 200 it can be twice the first (not always the same) or when I say 120 it can be 20% bigger than the first.

But any or all of 100, 200 and 120 I need them to stay the same and not lose 40 between them. (That's a very important point that you mentioned) Because if they lose 40 then all those parts will lose position.

 

[emvella]

When you change 80 to 120, how is it decided what other numbers change to make the sum 500?

500 is the previous answer. And 80 is the size of the part that can be edited later. So if I edit that part of 80 I don't need to start the job from the beginning.

 

[oldbrewer]

you have completely lost me....

 

[emvella]

you have completely lost me....

I know and I don't blame you

 

[emvella]

so any or all of 100,200,120 need to lose 40 between them

If you can do only the 2nd (200) and 3rd (120) losing 40 between them and the 1st (100) stays the same, maybe I still can work in another way.

 

[oldbrewer]

do you want them to lose 20 each or proportionately to their size ie 200 lose 25 120 lose 15

 

[emvella]

make it lose 20 each please.